hihocoder1829 Tomb Raider

思路：

暴力枚举。

实现：

 #include <iostream>
 #include <set>
 #include <vector>
 using namespace std;

 void get_subseq(string s, string x, int cur, set<string>& st)
 {
     if (cur == s.length()) { if (x != "") st.insert(x); return; }
     get_subseq(s, x + s[cur], cur + , st);
     get_subseq(s, x, cur + , st);
 }

 bool is_subseq(string s, string t)
 {
     int i = , j = ;
     while (i < s.length() && j < t.length())
     {
         if (t[j] != s[i]) j++;
         else i++;
     }
     return i == s.length();
 }

 bool check(string s, vector<string> v)
 {
     for (int i = ; i < v.size(); i++)
     {
         bool flg = false;
         int l = v[i].length();
         for (int j = ; j < l; j++)
         {
             string tmp = v[i].substr(j, l - j) + v[i].substr(, j);
             if (is_subseq(s, tmp)) { flg = true; break; }
         }
         if (!flg) return false;
     }
     return true;
 }

 int main()
 {
     int n;
     string s;
     while (cin >> n)
     {
         vector<string> v;
         for (int i = ; i < n; i++) { cin >> s; v.push_back(s); }
         set<string> st;
         vector<string> buf;
         get_subseq(v[], "", , st);
         for (auto it: st)
         {
             int l = it.length();
             for (int i = ; i < l; i++)
             {
                 string tmp = it.substr(i, l - i) + it.substr(, i);
                 buf.push_back(tmp);
             }
         }
         for (auto it: buf) st.insert(it);
         int maxn = ; string ans = "zzzzzzzzzz";
         for (auto it: st)
         {
             if (check(it, v) && (it.length() > maxn || (it.length() == maxn && it < ans)))
             {
                 ans = it;
                 maxn = it.length();
             }
         }
         if (ans == "zzzzzzzzzz") cout <<  << endl;
         else cout << ans << endl;
     }
     return ;
 }